Hold on!
Let me get this straight!
The user specifically comes in and says I AM MISSING CORTANA AND MISSING THE CORTANA OPTIONS IN THE SETTING.
This means the user cannot get into Cortana.
Your reply is "Hey I am a Windows 10 expert" Open Cortana?!
What the hell kind of answer is that?!
Your attention to detail needs a LOT of work if that is your answer.
By the way, I have the same issue and don't date tell me to open Cortana because it is MISSING! NOT THERE, GONE. DOESN'T EXIST. NO OPTION ON A RIGHT CLICK ON THE TASKBAR. ONLY OPTION IN SETTINGS IS CORTANA LANGUAGE. ALREADY TRIED TO REINSTALL WITH POWERSHELL, RAN SFC AND DISM.